Figure 5.

Human α1-antitrypsin (hAAT) promotes interleukin-10 (IL-10) -producing B cells and regulatory T (Treg) cells in a B-cell-dependent mechanism. (a) IL-10-producing B cells: splenocytes were isolated from IL-10-GFP transgenic mice, and cultured in 24-well plates at 3 × 10⁶ cells/well in 10 replicates. Lipopolysaccharide (LPS) (1 μg/ml) was added in the presence or absence of hAAT (0.5 mg/ml). CT, untreated cells. Seventy-two hours later, IL-10-positive cells were identified by FACS gated for surface CD19, B220 and CD1d. Right, representative FACS images. (b) Regulatory T cells: leukocytes were obtained from peripheral blood of wild-type mice, hAAT transgenic mice, chimeric hAAT/hAAT mice, B-cell knockout mice (BKO) and chimeric BKO/hAAT mice (n > 5 per group). FACS analysis, regulatory T cells are shown as % foxp3⁺ cells out of CD45⁺ CD4⁺ lymphocytes. Representative results out of two independent repeats. Mean ± SEM, *P < 0.05, **P < 0.01, ***P < 0.001.